Jarring apparatus



Nov. 29, 1960 M. B. CONRAD JARRING APPARATUS 3 Sheets-Sheet :1

Filed 001;. 1, 1957 INVENTOR. 1114977 E Can/e40 4rraen/zrs' Nov. 29, 1960 M. B. CONRAD 2,952,098

JARRING APPARATUS Filed Oct. 1, 1957 3 Sheets-Sheet 2 INVENTOR. Men/v B. Cat/e40 ATTO/QME/Si United States Patent ()fiice Patented Nov. 29, 1960 JARRIN G APPARATUS Martin B. Conrad, Downey, Calif., assignor to Baker Oil Tools, Inc., Los Angeles, Calif., a corporation of California Filed Oct. 1, 1957, Ser. No. 687,405

2 Claims. (Cl. 166-178) The present invention relates to subsurface well apparatus, and more particularly to apparatus for performing a jarring function in a well bore.

Jarring apparatus is used in a well bore for the purpose of delivering blows of comparatively great force to another device in the well bore. Resetting of the ap paratus while his in the well bore is desirable to enable repeated blows to be imparted to the other device. Resetting or recocking of the jarring apparatus has heretofore required its being subjected to a relatively high load or force which may not be readily available.

It is an object of the present invention to provide jarring apparatus which is capable of imparting repeated blows while in the well bore, and which can be placed in a reset or recocked condition through the imposition of relatively low forces thereon.

Another object of the invention is to provide jarring apparatus that is comparatively easy to reset after having been tripped.

A further object of the invention is to provide jarring apparatus which is capable of being reset repeatedly while in the well bore to deliver a plurality of blows, the apparatus tripping consistently upon being subjected to the same predetermined load or force.

An additional object of the invention is to provide jarring apparatus which consists of comparatively few parts, is relatively easy and economical to manufacture, and which is foolproof in its operation.

This invention possesses many other advantages, and has other objects which may be made more clearly apparent from a consideration of a form in which it may be embodied. This form is shown in the drawings accompanying and forming part of the present specification. It will now be described in detail, for the purpose of illustrating the general principles of the invention; but it is to be understood that such detailed description is not to be taken in a limiting sense, since the scope of the invention is best defined by the appended claims.

Referring to the drawings:

Figure 1 is a side elevational view of an apparatus embodying the invention disposed in a well casing;

Figs. 2 and 2a together comprise a longitudinal section, on an enlarged scale, of the apparatus shown in Fig. 1, Fig. 2a constituting a lower continuation of Fig. 2;

Fig. 3 is a view similar to Figs. 2 and 2a, showing the jarring apparatus in its tripped condition;

Fig. 4 is an enlarged cross-section taken along the line 44 on Fig. 3;

Fig. 5 is an enlarged cross-section taken along the line 5-5 on Fig. 3;

Fig. 6 is a fragmentary enlarged longitudinal section showing a portion of the jarring apparatus in its set condition;

Fig. 7 is a view corresponding to Fig. 6, illustrating the jarring apparatus at the instant of being tripped or released;

Fig. 8 is a view similar to Fig. 6, illustrating the jarring 2 apparatus in the initial stages of being reset or recocked;

Fig. 9 is a view similar to Fig. 6, illustrating the jarring'apparatus in a partially reset or recocked condi t1on.

The jarring apparatus A illustrated in the drawings is designed to deliver a longitudinally directed blow, as in an upward direction, to a lower tool B to which the jarring apparatus is suitably secured. The upper portion of the jarring apparatus may be attached to a sinker bar C which is, in turn, secured to a rope socket D to which the lower end of a wire line B, or corresponding 1 un ning-in string, is suitably attached.

The jarring apparatus A includes an inner mandrel 10, the upper end of which is threadedly secured to a sub 11 threadedly attached to the lower end of the sinker bar C. This mandrel is telescopically disposed within a housing 12, consisting of an upper housing section 13 having an upper head 14 threaded thereinto, this upper housing section being threadedly secured within the upper end of a lower housing section 15 having a lower end wall 16. The lower housing section is, in turn, threadedly attached to the lower tool B.

The mandrel 10 has a hammering head 17 at its lower portion adapted to be moved upwardly to strike a blow against the lower end 18 of the housing head 14, this blow then being transmitted through the housing 12 itself to the lower tool B. The mandrel 10 is disposed initially in a lower or set position, being releasably secured to the housing 12 by a releasable latch mechanism. As specifically disclosed, the upper portion of a jar sleeve 19 is threadedly secured to the lower end of the mandrel 10, the lower end of this sleeve having a transverse or end wall 20. Between its upper and lower ends 21, 20 the sleeve is provided with a plurality of circumferentially spaced, longitudinally extending slots 22, through its wall to provide a plurality of flexible beams or struts 23 between the upper and lower ends 21, 20

of the sleeve that are capable of deflecting in an inward direction, and in then returning to their normal position in an outward direction after the inward deflecting force has been released.

When the jarring apparatus is in its set condition, the jar sleeve 19 extends into the lower housing portion 15 and within a reset or recocking sleeve 24 which is also disposed within the lower housing section 15. This latter sleeve has an open upper end and an end wall 25 at its lower end. It is provided with a plurality of circumferentially spaced longitudinally extended slots 26 running from the lower end wall 25 to the upper end, to provide flexible arms 27 which are capable of being deflected in an outward direction and of returning to an initial inward position when the deflecting force is removed. The upper ends of these arms terminate in latch fingers 28, the outer surfaces 29 of which are inclined in an upward and inward direction for engagement against a companion tapered surface 30 provided by the lower end of the upper housing section 13. Such inclined surface 30 on the housing terminates at its upper end at a shoulder 31 normal to the axis of the apparatus, which can be engaged by the end 32 of each finger, which is also normal to the axis of the apparatus.

The flexible beams or struts 23 have cam elements 33 integral therewith at their intermediate portions which are adapted to be disposed below the fingers 28 when the latch apparatus is in a set condition, being received within inner recesses 34 in the upper portions of the arms. Each cam element 33 has an upper cam surface 35 inclined in an upward and inward direction and engageable with companion inner, lower cam surfaces 36 on the fingers." The lower surfaces 37 of the cam elements are tapered in an inward and downward direction, and are adapted to engage companion upper tapered inner surfaces 38 at the upper ends of the fingers 28 for the pur- -pose ofcamming the fingers 28 and the arms 27 outwardly when the apparatus is to be reset, in a manner described hereinbelow.

X when the fingers 28 engage the inclined and normal housing shoulders 3t), 31, such as disclosed in Figs. 2a and 6, the lower end wall 25 of the reset sleeve is spaced a short distance above the end wall 16 of the lower housing 15. Such spacing is provided to assist in the outward flexing of the arms 27 under the action of the cam elements 33 of the jar sleeve 19 when the apparatus is to be moved to a resetting or recocking position.

In the operation of the appartus, it may be lowered in the well bore or casing F with the mandrel telescoped downwardly within the housing 12, to space the mandrel head 17 below the housing head 14. At this time, the jaw sleeve 19 is disposed within the reset sleeve 24, with the cam elements 33 lying under the fingers 28 at the upper ends of the arms 27. When a jarring action or blow is to be imparted to the apparatus A, and from the apparatus to the particular lower tool B to which it is connected, an upward pull is taken on the wire line B which is transmitted through the sinker bar C, sub 11 and mandrel It) to the cam elements 33, this upward pull being transferred through the tapered cam surfaces 35, 36 to the fingers 28 and to the inclined and normal housing shoulders 30, 31. The housing 12 itself cannot move upwardly, since it is prevented from doing so by the lower tool B which may be anchored in the well casing F in some manner. The particular mode of securing the lower tool in the well casing forms no part of the present invention, and for that matter, it might be a device which is stuck in the well bore which it is desired to free through use of the jarring apparatus A.

As the upward pull on the wire line E increases, which pull is transmitted to the jar sleeve 19 and its cam elements 33, the coacting inclined faces 35, 36 on the cam elements 33 and fingers 28 cause an inward component of force to be exerted on the flexible beams or struts 23 to deflect them in an inward direction. The fingers 28 and arms 27 cannot move outwardly by virtue of the engagement of the ends 32 of the fingers with the normal shoulder 31 and because of the engagement of the inclined outer surfaces 29 of the fingers with the companion inclined shoulder 30 at the lower end of the housing section 13. As the upward force on the struts 23 and cam elements 33 increases, the greater is the amount of inward deflection of the flexible beams 23, un til the upwardly directed force is sufiicient to result in an inward deflection of the beams to the extent in which the cam elements 33 move inwardly of the inner ends of the tapered surfaces 36 on the fingers (Fig. 7). When such release occurs, the elasticity in the wire line E is such that it shortens substantially, much in the nature of a spring which has been relieved of a tensile pull, to rapidly move the mandrel 10 upwardly within the housing 12 to the extent determined by engagement of the mandrel head 17 with the housing head 14 (Fig. 3). Since the mandrel 10 moves at a rapid rate due to the sudden release of the cam elements 33 from the fingers 28, the mandrel head 17 will strike a very substantial blow upon the housing head 14, this blow being transmitted in an upward direction through the housing 12 to the well tool or device B therebelow.

If another blow is to be struck, then the apparatus A is reset. This is accomplished in a very simple manner, merely by lowering the wire line E, to lower the mandrel 10 within the housing 12 once again. In view of the space which initially existed between the lower end 25 of the reset sleeve 24 and the end wall 16 of the housing, such sleeve will move downwardly into contact therewith after the apparatus is tripped, providing a space between the upper ends 29, 32 of the fingers 28 and the adjacent tapered and normal shoulder 30, 31 on the lower end of the housing 13 (Fig. 8). Accordingly, as the mandrel 10 is lowered, the jaw sleeve 19 is moved back downwardly within the reset sleeve 24, the lower tapered cam surfaces 37 on the cam projections 33 engaging the up per ends 38 of the fingers. The weight of the sinker bar C, mandrel 10 and lower portion of the wire line B, if necessary, is imposed through the tapered surfaces 37 of the cam elements upon the fingers 28 and the arms 27 to expand and deflect the latter in an outward direction to the extent in which the cams 33 ride past the fingers 28 back into the arm recesses 34 under these fingers, such as disclosed in Fig. 9. During such downward movement of the mandrel and the jaw sleeve 19, the reset sleeve 24 cannot move downwardly since it is prevented from doing so by engaging the lower end wall 16 of the housing.

The arms 27 are relatively flexible, being much more flexible than the flexible beams or struts 23 of the jar sleeve 19, so that they are expandible outwardly as a result of the imposition of a relatively light downward force on the jar sleeve 24. Actually, little force is required to expand the arms 27 outwardly in moving the jar sleeve 19 back to a cooked position within the reset sleeve 24, as compared to the very substantial force required to effect an inward deflection of the beams 23 in releasing the jar sleeve 19 from the reset sleeve 24 and housing 12 when a hammer blow is to be struck against the housing head 14. The force necessary to deflect the arms 27 outwardly may be reduced considerably by making the angle of inclination of the lower cam surfaces 37 to the axis of the apparatus much less than the angle that the upper cam surfaces 35 make to the axis of the apparatus.

After the jar sleeve 19 has been repositioned Within the reset sleeve 24 and with the cam elements 33 disposed under the fingers 28, such as disclosed in Fig. 9, the wire line E, sinker bar C and mandrel 10 can again be moved in an upward direction, the reset sleeve 24 being shifted upwardly until the fingers 28 are again in contact with the inclined and normal shoulders 30, 31 at the lower end of the upper housing section 13, such as disclosed in Fig. 6. A predetermined pull must again be taken on the wire line B to secure the inward deflection of the flexible beams 23 and release of the jar sleeve 19 from the reset sleeve 24, the mandrel again moving upwardly within the housing 12 rapidly to strike another blow upon the housing head 14, which will be delivered through the housing 12 to the lower tool or device B.

The foregoing cycle of operation can be repeated as often as necessary, the jarring apparatus being recocked or reset merely by lowering the mandrel 10 relative to the housing 12, a blow being delivered merely by taking an upward pull on the wire line B and mandrel 10 of suflicient force.

For the purpose of facilitating the movement of the mandrel 10 within the housing 12, and also of the jar sleeve 19 within the housing, the upper housing section 13 is provided with circumferentially spaced longitudinally. extending slots 44 therethrough, the lower housing section 15 also being provided with circumferentially spaced longitudinally extending slots 41 therethrough. These slots 40, 41 provide a comparatively large passage area to permit the ready ingress and egress of the well bore fluid into and out of the housing sections, as a result of the rapid, telescopic movement of the mandrel 10 and jar sleeve 19 with respect to the housing sections 13, 15. Such fluid can also rapidly pass through the slots 26 in the reset sleeve to its interior as the jar sleeve 19 moves internally thereof, in order that the jar sleeve 19 does not tend to create any material Suction effect in the housing when it is moved rapidly upwardly within the housing, following release of the cam elements 33 from the fingers 28.

The jarring apparatus A consists of comparatively few parts; it can be made in economical manner; it is assemblable very readily; and it is found to have a long life. It can be designed to release at relatively light upward forces imposed on the wire line E, or other running-in string, or upon being subjected to comparatively great forces. Regardless of the magnitude of the upwardly directed forces required to trip the jar mechanism for the delivery of a hammer blow, the resetting action occurs as a result of the imposition of a rather small downward force. It has been found that despite repeated hammer blows imposed by the apparatus and its repeated resetting while in the well bore, the force at which the apparatus trips to deliver each hammer blow remains constant. Such tripping occurs at the single predetermined load at which the apparatus is designed to trip.

The inventor claims:

1. In jarring apparatus: an outer member; an inner member telescopically arranged within said outer member; said members having coengageable elements adapted to strike a blow upon one another; a jar sleeve secured at one of its ends to said inner member and having circumferentially spaced, longitudinally extending slots to provide flexible beams, said sleeve including a portion at its other end preventing lateral deflection of said beams at said other end; cam means on said beams at their intermediate portions; a reset sleeve adapted to be disposed around said jar sleeve, said recess sleeve being movable relative to said outer member and including flexible arms; means on said arms engageable by said cam means and outer member to couple said jar sleeve, reset sleeve and outer member to each other to transmit longitudinal forces in one direction between said members thereby to deflect said beams laterally to uncouple said cam means from said arms to permit said members to move longitudinally in one direction with respect to each other and said elements to strike one another; said means on said flexible arms and said outer member having coengageable surfaces normal to the axis of said members through which said longitudinal forces are transmitted; said coengageable surfaces moving away from each other upon uncoupling of said cam means from said arms; said cam means reengaging and deflecting said arms, upon relative longitudinal movement between said members in the opposite direction after said surfaces have disengaged, to recouple said cam means to said means on said arms.

2. In jarring apparatus: an outer member; an inner member telescopically arranged within said outer member; said members having coengageable elements adapted to strike a blow upon one another; a jar sleeve secured at one of its ends to one of said members and having circumferentially spaced, longitudinally extending slots to provide flexible beams, said sleeve including a portion at its other end preventing lateral deflection of said beams at said other end; cam means on said beams at their intermediate portions; a reset sleeve movable longitudinally relative to the other of said members and including longitudinally extending flexible arms; means on said arms engageable by said cam means and the other of said members to couple said jar sleeve, reset sleeve and said other member to each other to transmit longitudinal forces in one direction between said members thereby to deflect said beams laterally to uncouple said cam means from said arms to permit said members to move longitudinally in one direction with respect to each other and said elements to strike one another; said means on said flexible arms and said other of said members having coengageable surfaces normal to the axis of said members through which said longitudinal forces are transmitted; said coengageable surfaces moving away from each other upon uncoupling of said cam means from said arms; said References Cited in the file of this patent UNITED STATES PATENTS Beck Oct. 25, 1932 Stafford Apr. 6, 1943 

